This invention relates to an adjusting mechanism for a regulating device, in particular to an adjusting mechanism for a reducing valve.
Adjusting mechanisms are used in particular in pressure-reducing valves to adjust the force exerted by a spring on a piston acted upon by the pressure to be regulated, or on a diaphragm. Essentially two types of construction are known. In one construction, an adjusting spindle screws into a housing enclosing the spring, and acts on one end of the spring through a spring collar. In the other type of construction, the handwheel does not itself participate in the adjustment motion. In this instance, the spindle is supported rotatably but immovably in the axial direction within the housing and cooperates with a nut arranged in the housing and which is displaceable, but not rotatable.
The known construction with a rising handwheel requires a fairly large amount of space, while the other type is appreciably more difficult to fabricate and to assemble. The spindle has to be fitted from within the housing, and the dimensions of the end which is to receive the handwheel must be smaller than those of the seating collar. The profile for the nonrotational connection with the handwheel must therefore be fashioned afterwards, on the external end of the spindle.
It is the object of the present invention to improve the known adjusting mechanisms such as to facilitate fabrication of the adjusting spindle and insertion thereof into the housing.